Not RTFT so this may be discussed already but there's a difference between a show that comes to an end - for example, ER, Big Bang Theory both mentioned on the first page, both had a planned ending - and a show cancelled with storylines left unfinished. I might miss shows that ended, but cancelled shows are way more disappointing.
Mine would be recently Etoile and Kaos (more fool me for watching Kaos knowing it had been cancelled), and back in the 00s, Flashforward. Absolutely gutted by that one!